Stock pusher



STOCK PUSHER Filed Sept. 18, 1942 INVENTOR 6505 652220212 ATTORNEYPatented July 13, 1943 UNITED STATES PATENT OFFICE STOCK PUSHER GeorgeF. Zezula, Commerce, Mich. Application September 18, 1942, Serial No.459,066

2 Claims.

My invention is used in conjunction with automatic screw machines intheir various forms, such as modern multiple spindle machines, in whichthe stock to be worked upon, in the form of long rods, is fed into therespective machine by means of a suitable mechanism through the headstock spindle. The usual arrangement calls for a tube ending in a springcollet, which is located at the operative end of the spindle and throughwhich a length of stock is pushed outwardly towards and to a stopaligned with the mouth of the collet.

Positioned within the tube ending with a collet, is a pusher tube, beinga part of the mechanism serving to advance the stock through the collet,said pusher tube, terminating at its end, adjacent the collet, with apusher or push finger, to which my invention pertains.

Several kinds of said pushers are known in the industry, my improvementrelating especially to one of them, known as master pusher whichconsists of a cylindrical shell, made of high grade of spring tempersteel, split by long slots, extending in the direction of the axis ofthe shell, and removable pads, fitting into one end of said pusher andheld there firmly by keys, flanges or other means.

It will be understood that the bar stock, that is rods fed into therespective machine, are engaged by said pads, and as the pads are madeof a metal which is softer than the rods they soon wear out to a pointwhere their grip upon said rods is loose and ineiiective. When thisstage of wear was reached, it was necessary to remove the pushers as awhole, or the pads alone where this could be done, and to substituteother pads in their place. The operation was slow, diificult andexpensive as it often resulted in breakage of the cylindrical shellsholding the pads.

In order, therefore, to eliminat the above difiiculties, to prolong thelife of the pushers and to secure certain other advantages, I haveimproved the pushers, especially the master pushers in the manner whichwill be presently described, the specific purpose of my invention being:

To eliminate the necessity of removing the pads from the pushers, byproviding an easily removable and replaceable insert of splitconstruction, within the grip of said pads;

To provide an insert which upon wear may be easily adjusted and restoredto its initial degree of efiiciency without being removed from thepusher or the pads, respectively.

My further purpose is to provide an insert of simple construction whichmay be made of an easily available material such as brass, and whichtherefore, will cost comparatively little.

Having thus outlined the purposes of my invention, I shall now describemy improvement with reference to the accompanying drawing, in which:

Fig. l is an exploded perspective view of a pusher, including myremovable insert;

Fig. 2 is an exploded perspective view, magnified, of another species ofa pusher;

Fig. 3 is a longitudinal sectional view of the pusher shown in Fig. 1;

Fig. 4 is a longitudinal sectional view of the pusher shown in Fig. 21.

Similar numerals refer to throughout the several views.

The pusher shown in Fig. 1 comprises a cylindrical shell lfi, made ofhigh grade spring steel, said shell tapering towards what may bconsidered, its operative end, which will be presently described. At itsopposite end, the shell is provided with an external thread, thisserving as a means of afiixing the pusher to the end of the pusher tube,which is not shown here. The threaded part l2 extends from the end ofthe shell to an annular shoulder l l. The body of the shell is splitlongitudinally, parallel to its longitudinal axis, by means ofdiametrically disposed slots, which are marked iii, the outer ends ofthe parts separated by said slots, forming jaws M, opposed to eachother. Owing to the fact that the shell is made of spring steel, andowing to said slots I3, the jaws may be spread apart and are similarparts capable of exerting considerable pressure upon an object heldbetween them. Numeral l8 indicates an insert which is threadedexternally and which may be screwed into said jaws, the latter beingequipped with an internal thread indicated by numeral l5.

As a rule, the insert is made of brass and is of a somewhat largerdiameter than the internal diameter of the shell at the end encompassedby said jaws I 4. The insert is provided witha diametrical slot I I onits outer surface for the application of a screw driver, and contains acentrally located hole of a size suited to the diameter of the stockwhich is to be fed through the pusher.

The pusher shown in Figs. 2 and l, is substantially the same as that inFigs. 1 and 3, with the exception of its operative end, which includesadditional elements, known as pads. The shell 20 comprising anexternally threaded section 22; adjoining a shoulder 2!, is split bymeans of slots 23 to form two resilient members opposed to each otherand terminating in jaws 24. Each jaw contains an inner flange 35 and islined with a pad 26, extending between said flange and the shoulder 25.Both pads, when in place, form a cylinder or a sleeve splitlongitudinally, as shown, the split between the pads coinciding withslots 23. An inner shoulder 32 restricts the diameter of the openingbetween the pads at one end thereof, adjoining said shoulders 25. Inorder to secure the pads in place against rotary movement within jaws24, an integrally formed key 28 on one of the pads, fits into a slot 29within said flange 35 at the end of the respective jaw. I wish to addhere that the pads are Provided with an internal thread 33.

The operative member of the pusher which immediately engages the stockto be advanced thereby is an insert 30. The insert which is threaded onthe outside, is provided with a diametrical screw driver slot 3|, and acentral hole 36. Like in the case of the pusher shown in Figs. 1 and 3,the insert is of a somewhat larger diameter than the diameter of theopening between the pads, so that when the insert is screwed into itsplace between pads 26, it is held there tightly under the tension of theopposed sections of shell 20, split by means of slots 23.

I shall now describe the operation of my pushers. The pushers as nowused, are, as a rule, equipped with pads alone which after a period ofuse, become worn on the inner surfaces which come in contact with thestock passingbetween them. With the wear their usefulness is Aterminated and they have to be replaced by other pads. In the case of myimproved pushers, it is the insert which engages the stock to be fed. Asthe insert is made of substantially the same material as the pads, ittoo will wear out in about the same time. This, however, does not callfor its replacement. On the contrary the insert is left in place but itsuseful life may be prolonged by the simple expedient of sawing theinsert in half, in the plane of its longitudinal axis, along its screwdriver slot. After a while, when the wear of the inner surface of theinsert, now sawn in two, demands it, the operation may be repeated, andthe insert may be re-sawn in the same plane as before. This is possibleas the cut surfaces of the insert tightly abut each other under thetension of the jaws formed by the outer ends of the shell as abovedescribed. When desirable, the insert may be easily removed from betweenthe pads, by means of a screw driver, and a new one may be substitutedin its place.

It will be seen from the above description that my inserts not only takethe place of pads, which may be even omitted from pushers, but that theyrender a new service and furnish a new utility of which the pads are notcapable. This results from the feature which makes it possible first touse an uncut insert as a whole, and then to cut it in two, a number oftimes in succession and by bringing the cut parts close together toreduce the distance between the opposed inner surfaces of the passageleft therein for the moving stock. This is not feasible when pads areused.

I wish to point out that my improved pusher has already proved itsusefulness, practicability, and economy in actual use in an industrialestablishment.

I realize that further changes may be made in the construction of mypusher without departing from the inventive principle disclosed herein.What I, therefore, wish to claim, is as follows:

1. A stock pusher of the kind described, comprising a cylindrical shellof resilient metal, said shell being provided, at one end, with anexternal thread as a means of connecting it operatively to a pushertube, and being split, at the other end, into opposing members by aplurality of slots extending a part of the length of said shell,separate pads threaded on the inner surface for the inner side of eachend of said opposing members, and a removable cylindrical insert, heldbetween said pads under the tension of said members, said insert beingprovided with a central hole for admission of stock.

2. A stock pusher as described, comprising a cylindrical shell ofresilient material, said shell being provided, at one end, with anexternal thread, and being split 'at the other end, into opposingmembers by a plurality of slots, extending a part of length of saidshell, separate pads, threaded on the inner surface and being held onthe inner side at the end of each of the opposing members, and anexternally threaded cylindrical insert, held between said pads under thetension of said members, said insert being provided with a central holefor admission of stock and a diametrical slot on its face forapplication of a screw driver.

GEORGE F. ZEZULA.

